This advisory expires at Midnight.
Huntington Ravine has MODERATE and LOW avalanche danger. Central, Pinnacle, and Odell Gullies have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain features carefully. North, Damnation, Yale and South have Low avalanche danger. Natural and human triggered avalanches are unlikely. Escape Hatch is not rated due to a lack of snow.
Tuckerman Ravine has MODERATE and LOW avalanche danger. Right Gully, Sluice, the Lip, Center Bowl, Chute, Left Gully and Hillmans Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Heightened avalanche conditions on specific terrain features exist. Evaluate snow and terrain features carefully to identify features of concern. Lobster Claw has Low avalanche danger. Natural and human-triggered avalanches are unlikely. Little Headwall and Lower Snowfields are not rated due to lack of snow.
AVALANCHE PROBLEM: A natural avalanche with a crown approximately a meter high and 20m wide was reported around noon yesterday in the area of the left side of the Center Bowl and right of the Chute. The 6” of new snow which fell yesterday loaded into our terrain on strong W and WNW winds. Wind slabs reactive to human triggering remain scattered through our terrain. Larger snowfields, which have grown in size quite a bit over the past 10 days should be approached cautiously. Discontinuous slopes with lots of anchors showing could still harbor reactive wind slabs, just on a smaller scale. Lots of cliffs and boulders would do some damage if even a small pocket were triggered.
WEATHER: The coldest temperatures of the season so far will settle in for the day with a high temperature of -5F forecast for the summit. Northwest winds will die down a bit today. New wind loading will stop as well, not just due to the diminished velocity but also due to the fact little loose, new snow remains in place in the alpine zone to be carried. Current wind speeds in the 50 mph range will diminish further through the day ultimately blowing from the northwest at 35-50 mph.
SNOWPACK: Unfortunately, poor visibility has hampered our ability to gather more accurate visual info this morning. We are pretty confident in the low ratings of northern gullies in Huntington since wind speeds in the 90’s mph scour out snow. Other areas rated moderate contain wind slabs in a range of thicknesses which are also likely to be stubborn. That said, I would remain cautious and do lots of hand shears while traveling anywhere today. Steeper lee slopes may have greater instabilities due to the thickness of the wind slab along with the sensitive of weak snow beneath from last weeks lower density snow on light winds. These slabs are also perforated by many barely submerged boulders and terrain features. We’ve received 38” of snow so far this month with no significant melting events.
Remember that the bridge work continues on the Tucks Trail so use the detour on the Huntington Ravine trail. Some folks may opt to skin up the Sherburne trail so be on the lookout for them and for machinery on the ski trail. Be on the lookout for construction debris at crossover number 7 around a mile down from Hermit Lake. Be sure to report any avalanche activity or snowpack observations through our observation link under the Resources tab above. Internet connections continue to be challenging so check posted advisories at slatboards.
- Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
- Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
- For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
- Posted 8:30 a.m., Saturday, December 10, 2016. A new advisory will be issued tomorrow.
Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716